求大神，关于C语言的问题

Question

我想写多个字符串， 每个字符串是一个单词， 单词间以空格隔开 当输入回车键时自动结束整个输入表示一个句子， 并且内存是动态分配的， 不确定有多长， 该咋写啊
用二维数组 或者指针数组加malloc 简洁明了的

Answer 1

分两种情况，如果你能够确定句子的最大长度，可以用下面的写法：

 int main()
{
    char str[1024]  = {0};
    char* pstr  = str;
    char* pos   = str;
    char** result;
    fgets(str , 1024 , stdin);
    int space_count = 0;
    while (*pstr != '\0')
    {
        if (*pstr++ == ' ')
            space_count ++;
    }
    pstr = str;
    result  = (char**)calloc(sizeof(char*) , space_count + 1);
    for (int i = 0 ; i <= space_count ; i ++)
    {
        while (*pstr != ' ' && *pstr != '\0')
            pstr ++;
        *pstr++ = '\0';
        printf("%d:%s\n" , i , pos);
        result[i]   = malloc(sizeof(strlen(pos)));
        strcpy(result[i] , pos);
        pos = pstr;
    }

    for(int i = 0 ; i <= space_count ; i ++)
        printf("%s\n" , result[i]);
    return 0;
}

如果你完全什么都不确定，只能用更复杂的写法：

 int main()
{
#ifndef WORDLIMIT
#define WORDLIMIT 10
#endif
    char* tmpword   = calloc(sizeof(char) , WORDLIMIT);
    char** result   = NULL;
    char ch;
    int curlimit      = WORDLIMIT;
    int wordlen     = 0;
    int mul = 1;
    int wordcount   = 0;

    while ((ch = getche()) != '\n' && ch != '\r')
    {
        if (ch != ' ')
        {
            if (wordlen == curlimit)
            {
                tmpword = realloc(tmpword , (curlimit + WORDLIMIT) * sizeof(char));
                if (!tmpword)
                    exit(-1);
            }
            tmpword[wordlen ++] = ch;
        }
        else
        {
            tmpword[wordlen] = '\0';
            wordcount ++;
            result  = realloc(result , wordcount * sizeof(char*));
            if (!result)
                exit(-1);
            result[wordcount - 1]   = malloc(sizeof(char) * strlen(tmpword));
            strcpy(result[wordcount - 1] , tmpword);
            wordlen = 0;
            mul = 1;
            curlimit  = WORDLIMIT;
        }
    }
    //处理最后一个单词
    if (wordlen == curlimit)
    {
        tmpword = realloc(tmpword , (curlimit + WORDLIMIT) * sizeof(char));
        if (!tmpword)
            exit(-1);
    }
    tmpword[wordlen] = '\0';
    wordcount ++;
    result  = realloc(result , wordcount * sizeof(char*));
    if (!result)
        exit(-1);
    result[wordcount - 1]   = malloc(sizeof(char) * strlen(tmpword));
    strcpy(result[wordcount - 1] , tmpword);

    for (int i = 0 ; i < wordcount ; i ++)
        printf("\n%s" , result[i]);
    return 0;
}

第二种方法很不好用，也可能是我没写好没有优化的原因，但是就这样的写法而言，一旦输错了一个字，输入退格是没有用的。